A dark, coarse-grained plutonic rock of crystalline texture, consisting mainly of pyroxene, plagioclase feldspar, and often olivine.
- ‘The highest core recovery occurs in the massive olivine gabbro, which contain lower densities of fractures and are generally undeformed.’
- ‘Jansen also describes gabbro, diabase, ultrabasic rocks and Permian limestones in a comparable section on Naxos.’
- ‘Contacts between plutons of gabbro or hybrid rock and granite are commonly marked by net-vein complexes.’
- ‘The deepest layer is gabbro, coarse-grained but chemically equivalent to basalt, which forms when magma cools and crystallizes slowly.’
- ‘Permian and Triassic plutonic complexes comprise monzonite, granite, granodiorite or tonalite with minor gabbro and diorite.’
Mid 19th century: from Italian, from Latin glaber, glabr- ‘smooth’.
We take a look at several popular, though confusing, punctuation marks.